One feature that I believe would help immersion is a simple button that would open up a chat window where you could type a message that would then be displayed above your character.
As the GM you could create individual dialogue on the fly by possessing a character, popping up the window, and displaying the dialogue above the NPC. Hopefully it would have some minor formatting to allow for the GM to italicize expressions or actions. Walking around the world and seeing a character standing there with something like an "Eyes you suspiciously" would allow for a nice rhythm for interactions. You could also easily distinguish between in-game dialogue and events and metagame discussion as well. Any other thoughts? I am trying to find a simple, elegant system that could work for dialogue and possibly even be a stand in for the lack of executable animations.